Hey thank you for taking the time I appreciate your response.. and I hope it helps some people with a similar problem.

And thank you to everyone who has shared their answers and ideas, but that doesnt have anything to do with the original problem with using Lightroom and the curves panel.

I can't believe it has been over a year and several LR, Wacom, MacOS, and Creative Cloud updates and this problem still exists. I have even upgraded my system to a fully loaded iMac and the problem is still persistent.

For those of you that are not following with what I had originally posted as the problem...

When in Lightroom CC2015.6 (or previous versions), using a Wacom Intuos Pro with the latest upgrades (I've tried several older software versions as well), on an iMac with OSX El Capitan 10.11.6, (also happened on Mavericks and Yosemite), if you try to manipulate the CURVES palette, the pointer will not smoothly transition or move the points on the curve. If you use a mouse it works just fine. Or if using "Mouse mode" shortcut trick like some other had posted, that works as well. But simply using the pen in normal mode, with all different tip stiffness and adjustment levels, I can't move any points on the curve without it jumping around erratically. It is completely unusable.

This problem exists for me on 3 different Mac machines (2 iMac's and a MacBook Pro). Everything else works fine. Sliders, brushes, etc. Also, this problem does not exist in Camera Raw, or in Photoshop.

I've revisited this and I think I see what you are referring to. It is somewhat subtle what is happening, but let me explain my findings and see if you are experiencing the same.

While moving a point on the tone curve around with my Wacom stylus, sometimes the point will refuse to move or move somewhat erratically. What I discovered is that my cursor and the point are not moving together. This is especially true when moving upward or to the right. Downward and to the left have a lesser effect. To illustrate this, click on a point that is low on the curve and move it upward. When you let go, the cursor will reappear and it will not be on top of the point. Instead, the cursor will have moved further up. Now click this same point and move it back down. When you let go this time, the cursor will be much closer to the point, if not directly on top of it. The same happens when moving to the right when compared to moving to the left. The movement to the right is really significant because the cursor will hit the edge of the screen very quickly, preventing you from moving the point further to the right. The same can happen when moving the point upward, especially if you repeatedly move the point up and down. This limiting of the movement to the right or up can make it seem like the point isn't doing what you want and it only gets worse the harder you try. This can also make it likely that you'll end up moving the point in some direction that causes the point to become invalid and get removed (moving it off the graph or past another point on the graph).

If you can verify this is the behavior you are seeing as well, then we can get this reported to engineering for repair.

The workaround is to only move points a little at a time before letting go of and re-clicking the point, especially when moving up and to the right. Big, sweeping movements of the stylus while clicked on a point should be avoided.

Yes this is exactly what has been happening. But for me, even the smaller movements of the points cause erratic behavior as well. It is nearly impossible to move the anchors or points on the curve smoothly at all in any direction. No matter how small the movements. I just tested using your description about where the cursor reappears and mine functions exactly as you stated.

When moving up, upon release, the cursor is at the top of the curves graph and not on the point. The same to the right. When moving in either direction however, the points and cursor slam themselves to the max and cannot be slowly moved. For example, say I'm going to make a contrast curve with an anchor point in the middle. If i try to pull down the shadows, as soon as I press down with the pen it will always try to pull the cursor down and to the left corner, sometimes even when holding the pen still. If I try to push the highlights half up, it will jump all the way to the top and try to pull left as well. And each time I release, the cursor is in a different spot just as you stated.

I hope that helps.. but it sounds like you know exactly what I am experiencing.

I have had the same problems as JAlanPaul using a Wacom Intous Pro tablet and wrote a bug report over a year ago and sadly these issues still remain. OS X is now named mac OS 10.12, the only compatible Wacom driver is 6.3.18-4 and their user forum is gone.

Adobe CC Lightroom is up to version 2015.7 but the RGB curves picker and HSL pickers suffer from jerky adjustment and interaction, as described previously. All other Adobe applications are not affected and fine. Let's hope Adobe acknowledge this and releases a totally reworked LR 2017 including better GPU acceleration as PS does.

So I thought; if this erratic behaviour was due to poor sensivity at the borders of the Wacom tablet (which some Wacom drivers have shown) the problem wouldn't appear if I scaled the LR curves histogram to the full tablet area, as shown in screendump. But the issue persisted and was actually, if not amplified, very obvious.

Good luck in squashing this bug who has lived on since the introduction of LR CC!

Hi Henke, nice try but no, this is not an issue with sensitivity at borders, same movements performed in other applications are perfect, we're talking 3-5 cm from borders in some cases, it's really a LR+wacom Driver issue.

What do you know.. this bug that seems to have been haunting us for ages is squashed as of LR 2015.8 in conjunction with Wacom driver 6.3.19-10 running macOS 10.12.2 and using a Wacom Intous Pro (PTH-651). I just had to pull the curve a couple of extra time just to make sure, but it's all good. Thanks!

I've just upgraded to a new Macbook Pro (2016 touchbar version) and have found this exact same problem when trying to adjust the tone curve points with the standard built-in trackpad. Ironically, I had no problems with this on my older Macbook Pro (mid-2010 version). Is this a known problem? It's infuriating to say the least.